Aluminium foil lamination is widely regarded as the most effective barrier material in flexible packaging, giving almost perfect protection against light and suppressing any transport of matter.
Foil is usually converted to flexible packaging laminates by traditional converting processes, such as 2-component adhesive lamination.
Almost all aluminium is put through an annealing process, to produce an appropriate surface, which is as good and homogeneous as possible with regard to unwinding properties (at high speed), wettability, foil laminating adhesive with good adhesion and chemical resistance.
the main reason for using aluminium foil in flexible packaging lies in the need to completely suppress migration or permeation through the package and shield the packaged good from the environment in the most suitable way. To achieve good adhesion of a coating on foil, good spreading of the coating is an essential pre-requisite, to be fulfilled. Good wetting and spreading of the matter to be coated on the aluminium foil is fulfilled, if the coating’s surface tension is similar to or falls below the foil’s surface tension.
